(1. Jiangxi Key Laboratory of Disaster Prevention-mitigation and Emergency Management，East China Jiaotong University，Nanchang，Jiangxi 330013，China；2. School of Civil Engineering and Architecture，East China Jiaotong University，Nanchang，Jiangxi 330013，China；3. Key Laboratory of Road Structure and Material of Ministry of Transport(Changsha)，Changsha
University of Science and Technology，Changsha，Hunan 410114，China；4. School of Civil Engineering，Changsha
University，Changsha，Hunan 410022，China；5. State Key Laboratory of Geomechanics and Geotechnical
Engineering，Institute of Rock and Soil Mechanics，Wuhan，Hubei 430071，China)
Abstract：Due to the brittleness of rock and irregular joint，block-flexure is the most common type of toppling failure in anti-dip bedding rock slopes. Firstly，the failure mechanism of block-flexure toppling was clarified by centrifugal model test. A mechanical analysis model of block-flexure toppling was established. Then，based on the limit equilibrium method，the mechanical analytical formulas for the stability of continuous column and blocky column were derived respectively. The failure surface of block-flexure toppling was searched by the search algorithm. Finally，the whole analysis process was realized by MATLAB programming. The results show that the slope subjected to block-flexure toppling failure can be divided into four subzones(a toppling failure zone，a crack zone，a deformation zone and an unaffected zone). The failure surface of block-flexure toppling is stepped，and the height of these steps is equal to the multiple of the spacing of cross joints. It is found that the results of the theoretical analysis method are mutually verified with the results of centrifugal test. Then，the influencing factors were analyzed by the theoretical method. It is found that the inclination of cross-joint and inclination of slope face have a great influence on the scope of the first toppling failure zone；the thickness of column，tensile strength and the inclination of cross-joint have a great influence on the critical instability height. The research results can provide theoretical support for disaster prevention and control of the slope.
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2023, Vol. 42 
